Prandtl Number Calculator
What is a Prandtl Number Calculator?
A Prandtl Number Calculator is a tool used to compute the Prandtl number (Pr), which is a dimensionless number in fluid dynamics and heat transfer. It helps analyze the relationship between momentum diffusivity (viscosity) and thermal diffusivity of a fluid.
Why Use It?
The Prandtl number determines whether heat conduction or convection dominates in a fluid. It is crucial in designing heat exchangers, aerodynamics, and fluid flow applications.
How Does It Work?
The Prandtl number is calculated using the formula:

where:
- ν = kinematic viscosity (m²/s)
- α = thermal diffusivity (m²/s)
- μ = dynamic viscosity (Pa·s)
- Cp = specific heat capacity (J/kg·K)
- k = thermal conductivity (W/m·K)
You input these values, and the calculator computes Pr.
When is it Used?
- Low Pr (<1): Heat conduction dominates (e.g., liquid metals).
- Pr ≈ 1: Balanced (e.g., air, water at moderate temperatures).
- High Pr (>1): Convection dominates (e.g., oils).